Hello , I have some Bitcoin in a portable elecron wallet  which is on my pen drive . Now if I try to transfer the bitcoin to an address in Localbitcoin or any other address , it says "error: server didn't respond " . My electron version is 2.9.0 , which is quite old .  Maybe this is the reason I am unable to send the bitcoin . And I am unable to upgrade it to current version . How do I upgrade ? And if I download the 4.0.3 version , it just doesn't open in my computer .